Are you suggesting that there's no such thing as the "Foxborough Flu?"
While this is something that we'll never know about for sure, a common sense perspective exists that may point otherwise when it comes to red shirting players or retaining their rights for lesser injury than has been suggested when placed on IR.
There's nothing "wrong" per se about it, especially when roster spots are at such a premium, but there is definitely some grey area here depending on personal opinion. In other words, there are some players who could return by October, but since they aren't expected to contribute much anyway, they will be placed on IR. Call it what you want, and you'd be right in pointing out that every single team does it, but it definitely happens.
We've also seen the choice to leave a player on PUP for the entire year, which often voids their contractual year like in the case of Myron Pryor. Same decision, different designation.